Search results for "brain"
showing 10 items of 3997 documents
Motor abnormalities and basal ganglia in first-episode psychosis (FEP)
2020
AbstractBackgroundMotor abnormalities (MAs) are the primary manifestations of schizophrenia. However, the extent to which MAs are related to alterations of subcortical structures remains understudied.MethodsWe aimed to investigate the associations of MAs and basal ganglia abnormalities in first-episode psychosis (FEP) and healthy controls. Magnetic resonance imaging was performed on 48 right-handed FEP and 23 age-, gender-, handedness-, and educational attainment-matched controls, to obtain basal ganglia shape analysis, diffusion tensor imaging techniques (fractional anisotropy and mean diffusivity), and relaxometry (R2*) to estimate iron load. A comprehensive motor battery was applied incl…
Cognitive impairment in schizoaffective disorder: a comparison with non-psychotic bipolar and healthy subjects.
2007
Objective: Only a few studies have examined specifically the neuropsychological performance of schizoaffective patients. Method: The sample consisted of 34 euthymic DSM-IV schizoaffective patients, who were compared with 41 euthymic bipolar patients without history of psychotic symptoms and 35 healthy controls. Euthymia was defined by a score of 6 or less at the Young Mania Rating Scale and a score of 8 or less at the Hamilton Depression Rating Scale for at least 6 months. Patients were compared with several clinical, occupational, and neuropsychological variables such as executive function, attention, verbal and visual memory and the two groups were contrasted with 35 healthy controls on…
Neurodevelopmental subtypes of bipolar disorder are related to cortical folding patterns: An international multicenter study
2018
Objectives Brain sulcation is an indirect marker of neurodevelopmental processes. Studies of the cortical sulcation in bipolar disorder have yielded mixed results, probably due to high variability in clinical phenotype. We investigated whole-brain cortical sulcation in a large sample of selected patients with high neurodevelopmental load. Methods A total of 263 patients with bipolar disorder I and 320 controls were included in a multicentric magnetic resonance imaging (MRI) study. All subjects underwent high-resolution T1-weighted brain MRI. Images were processed with an automatized pipeline to extract the global sulcal index (g-SI) and the local sulcal indices (l-SIs) from 12 a priori dete…
Early age of onset, brain morphological changes and non-consistent motor asymmetry in schizophrenic patients.
1999
Previous data suggest abnormalities in the consistence of motor dominance in schizophrenia (e.g. mixed-handedness, poor correlation between hand, eye and foot preferences and an increase of hand-eye crossed dominance). The aim of this work is to examine the clinical significance of hand-eye and hand-foot crossed dominance in a sample of 61 right-handed schizophrenic patients. The application of multivariate analysis revealed that 23 right-handed and non-right-eyed patients (crossed hand-eye dominant group) had a significant earlier clinical onset and smaller brain size, global and frontal area, than 38 right-handed and right-eyed schizophrenics (consistent hand-eye dominance group). These f…
Subchronic haloperidol downregulates dopamine synthesis capacity in the brain of schizophrenic patients in vivo
2003
Udgivelsesdato: 2003-Apr The antipsychotic effect of neuroleptics cannot be attributed entirely to acute blockade of postsynaptic D(2)-like dopamine (DA) receptors, but may arise in conjunction with the delayed depolarization block of the presynaptic neurons and reduced DA synthesis capacity. Whereas the phenomenon of depolarization block is well established in animals, it is unknown if a similar phenomenon occurs in humans treated with neuroleptics. We hypothesized that haloperidol treatment should result in decreased DA synthesis capacity. We used 6-[(18)F]fluoro-L-dopa (FDOPA) and positron emission tomography (PET) in conjunction with compartmental modeling to measure the relative activi…
Abnormal motor asymmetry only during bimanual movement in schizophrenic patients compared with healthy subjects.
2003
In schizophrenia, research on motor asymmetry has focused on the direction and the degree of handedness using unimanual motor tests and tasks. However, typically both hands collaborate in the production of most manual movements. This study explored motor asymmetry exhibited during unimanual and bimanual tasks in schizophrenic and healthy subjects using a new experimental motor battery. Specifically, the authors investigated the motor indices of laterality during finger-tapping and hand-turning tasks in four unimanual and four bimanual conditions in 84 schizophrenic and 31 healthy subjects, all right-handed. The schizophrenic patients showed reduced motor asymmetries only during bimanual tap…
Human dopamine receptor D2/D3 availability predicts amygdala reactivity to unpleasant stimuli
2009
r r Abstract: Dopamine (DA) modulates the response of the amygdala. However, the relation between dopa- minergic neurotransmission in striatal and extrastriatal brain regions and amygdala reactivity to affective stimuli has not yet been established. To address this issue, we measured DA D2/D3 receptor (DRD2/3) availability in twenty-eight healthy men (nicotine-dependent smokers and never-smokers) using positron emission tomography with ( 18 F)fallypride. In the same group of participants, amygdala response to unpleasant visual stimuli was determined using blood oxygen level-dependent (BOLD) functional mag- netic resonance imaging. The effects of DRD2/3 availability in emotion-related brain …
TC perfusionale nell'ischemia cerebrale acuta: Valore predittivo dei parametri di perfusione cerebrale nel discriminare il tessuto vitale da quello i…
2007
Purpose. The aim of this study was to assess the value of computed tomography (CT) perfusion parameters in differentiating tissue viability in acute stoke patients. Materials and methods. Thirteen patients (mean age 63.3 years) with nonhaemorrhagic stroke underwent multidetector perfusion CT within 3 h of symptom onset. Images were continuously acquired at the basal ganglia over 40 s during injection of 90 ml of iodinated contrast medium injected at a rate of 9 ml/s with a 9-s delay. Z-axis coverage was 20 mm. All patients underwent diffusion-weighted magnetic resonance imaging (DWI) within 12 h of perfusion CT to define the extent of the infarct. Perfusion CT data were analysed in regions …
Maternal history of reading difficulty is associated with reduced language-related gray matter in beginning readers.
2012
Family history and poor preliteracy skills (referred to here as familial and behavioral risk, respectively) are critical predictors of developmental dyslexia. This study systematically investigated the independent contribution of familial and behavioral risks on brain structures, which had not been explored in past studies. We also examined the differential effects of maternal versus paternal history on brain morphometry, and familial risk dimensionally versus categorically, which were also novel aspects of the study. We assessed 51 children (5 to 6 years of age) with varying degrees of familial and behavioral risks for developmental dyslexia and examined associations with brain morphometry…
Motor recruitment during action observation: Effect of interindividual differences in action strategy
2020
Abstract Visual processing of other’s actions is supported by sensorimotor brain activations. Access to sensorimotor representations may, in principle, provide the top-down signal required to bias search and selection of critical visual features. For this to happen, it is necessary that a stable one-to-one mapping exists between observed kinematics and underlying motor commands. However, due to the inherent redundancy of the human musculoskeletal system, this is hardly the case for multijoint actions where everyone has his own moving style (individual motor signature—IMS). Here, we investigated the influence of subject’s IMS on subjects’ motor excitability during the observation of an actor…